Establishment and Characterization of a Steroidogenic Human Granulosa-Like Tumor Cell Line, KGN, That Expresses Functional Follicle-Stimulating Hormone Receptor

Abstract

We established a steroidogenic human ovarian granulosa-like tumor cell line, designated KGN, from a patient with invasive ovarian granulosa cell carcinoma. KGN had a relatively long population doubling time of about 46.4 h and had an abnormal karyotype of 45,XX, 7q-, -22. A steroid analysis of the cultured medium by RIA performed 5 yr after the initiation of culture showed that KGN was able to secrete pregnenolone and progesterone, and both dramatically increased after stimulation with (Bu)(2)cAMP. However, little or no secretion of 17alpha-hydroxylated steroids, dehydroepiandrosterone, androstenedione, or estradiol was observed. The aromatase activity of KGN was relatively high and was further stimulated by (Bu)(2)cAMP or FSH. These findings showed a pattern similar to that of steroidogenesis in human granulosa cells, thus allowing analysis of naturally occurring steroidogenesis in human granulosa cells. Fas-mediated apoptosis of KGN was also observed, which mimicked the physiological regulation of apoptosis in normal human granulosa cells. Based on these findings, this cell line is considered to be a very useful model for understanding the regulation of steroidogenesis, cell growth, and apoptosis in human granulosa cells.

Egonol gentiobioside and egonol gentiotrioside from Styrax perkinsiae promote the biosynthesis of estrogen by aromatase

“…1A, the 17b-estradiol concentration was significantly increased in KGN cells by using testosterone as a substrate, indicating that KGN cells constitutively express high amounts of aromatase, as previously reported (Nishi et al, 2001;Ohno et al, 2004). Forskolin significantly increased the production of 17b-estradiol.…”

“…Egonol gentiobioside and egonol gentiotrioside promote estrogen biosynthesis through aromatase KGN cells cannot synthesize androgen or estrogen by themselves due to the absence of 17a-hydroxylase (Nishi et al, 2001), and an aromatase inhibitor completely abolished the effect of egonol gentiobioside and egonol gentiotrioside on 17b-estradiol biosynthesis in KGN cells (Fig. 2B) and 3T3-L1 cells (Fig.…”

Icariin from Epimedium brevicornum Maxim promotes the biosynthesis of estrogen by aromatase (CYP19)

“…KGN cells lack endogenous 17a-hydroxylase and cannot synthesize androgens or estrogens de novo (Nishi et al, 2001). Therefore, the effect of icariin on 17b-estradiol biosynthesis in the presence of testosterone may be caused by aromatase, the only enzyme able to convert testosterone to 17b-estradiol.…”

Differential apoptotic activities of wild-type FOXL2 and the adult-type granulosa cell tumor-associated mutant FOXL2 (C134W)

“…To assess the effects of WT and mutant FOXL2 on cell survival and death, we measured cell viability using flow cytometry after the overexpression of the two FOXL2 proteins in KGN cells (Nishi et al, 2001) derived from human GCTs. Overexpression of WT FOXL2 significantly increased the number of Annexin V-positive apoptotic cells, and overexpression of mutant FOXL2 clearly induced lower levels of cell death compared with the WT protein ( Figure 1a).…”